Question

A stone tied to $180cm$ long string at its end is making $28$ revolutions in horizontal circle in every minute. The magnitude of acceleration of stone is $\frac{1936}{x}m{s}^{-2}$. The value of $x$ _____
( Take $\pi =\frac{22}{7}$ )

Answer 1

Answer: 125

$a={\omega }^{2}R={\left(\frac{28\times 2\pi }{60}\right)}^2\times 1.8$
$={\left(\frac{56}{60}\times \frac{22}{7}\right)}^2\times 1.8$
$=\frac{(44{)}^2}{225}\times 1.8$
$=\frac{1936\times 1.8}{225}$
$x=125$